Doors



P. J. MCGIRR Feb. 3, 1970 DOORS 2 Sheets-Sheet 1 Filed Aug. 12, 1968Feb. 3, 1970 .M.C. 3,493,033

DOORS Filed Aug. 12. 1968 2 Sheets-Sheet 2 W H n w a a w u 5 r a 8 8 THOH0 1 n lull/V v m w 3 o n2 u h I f I I l I I I l I I l l I I I I I I IIII I I I I I I I I I l I L, L

United States Patent 3,493,033 DOORS Patrick Joseph McGirr, 2 KilharrackAve., Dublin 5, Ireland Filed Aug. 12, 1968, Ser. No. 752,035 Int. Cl.E05d /26; E05f 11/02 U.S. Cl. 160-207 13 Claims ABSTRACT OF THEDISCLOSURE A foldable door for a delivery van having upper and lowerdoor sections hingably connected together, pivot means connecting theupper door section to the top of a door in said van, track meansalongside the edges of said door, and biasing means secured to one ofthe door sections adapted to exert a leverage upon the other doorsection.

This invention concerns foldable doors of the kind which comprise aplurality of sections hinged together, the door hinges, as also thehinges between the sections having their pivotal axes arrangedhorizontally. A door of this kind is described, for example, in Britishpatent specification No. 1,017,836, as applied to a van body, with thedoor at the rear of the van hinged to the van body and counterbalancedso that it is a simple matter to raise or lower the door wheneverdesired, the sections of the door folding towards each other as the dooris raised. Very little effort on the part of the attendant is thusrequired to move the door either up or down, to expose or cover the dooropening as desired.

In the construction described in the aforesaid patent specification, thelower door section is guided at the bottom in vertical tracks at eitherside of the door opening so as to be movable upwards beneath the upperdoor section, and in order to counter-balance a substantial portion ofthe weight of the door, a spring-loaded roller is mounted horizontallynear the top of the door opening, tapes which are attached at their freeends to the lower door portion being wound on the roller. An object ofthe present invention is to provide an improved construction whereby theweight of the door sections is substantially counter-balanced in asimple manner without employing a spring-loaded roller upon which tapesattached to the lower door section may wind or unwind as the door israised or lowered. The present invention also provides an improved hingeconstruction for the mounting of the door.

Although in carrying out the invention it is necessary to provide avertical track at each side of the door opening in order to guide thebottom of the door to move in a vertical plane, the fact that a springroller adjacent to the top of the door is dispensed with also enablesthe hinges at the top of the door, if desired, to be pivoted on theinside and to pass below, the top rail of the door opening instead ofpassing over said top rail, so that when the door is closed the hingesare not visible from the outside of the door (i.e. from the side of thedoor opening on which the door is adapted to open).

Accordingly the invention provides a foldable door of the kind referredto wherein the lower door section is guided at the bottom by verticaltracks, one at each side of the door opening, and a force tending tofold said lower door section towards the upper door section to which itis hinged is applied by spring means secured to one of the door sectionsand adapted to exert a leverage upon the other door section. Thearrangement may be so contrived that the point of application of thespring force tending to fold the lower door section towards the upperdoor section changes as the angle between the door secice tions changesin such a way as substantially to compensate for the increase ordecrease in the spring tension which occurs as the angle between the twodoor sections increases or decreases. Preferably the spring means whichadvantageously comprise coiled springs, torsion bars or the like, aremounted in a radial position on one of the door sections so as to exerta turning moment upon the other door section hinged thereto, through theagency of a lever arm, the free end of which movably engages the lastmentioned door section.

According to a further feature of the invention the upper door sectionis carried by hinges mounted adjacent to the horizontal rail whichdefines the top of the door opening with their pivot pins on theopposite side to that on which the door is adapted to open, said hingeshaving U-shaped portions which pass through the door opening beneathsaid rail and thereby raise the upper end of the upper door sectionabove said opening when the door is fully open. This enablessubstantially the full height of the door opening to be utilised. Theconstruction may be so carried out that when the lower door section isin its fully open position, the upper door section lies at an anglethereto while the lower door section is in such a position relatively tothe guide tracks that the forces acting on the lower door sections, dueto their respective weights and the reaction of said tracks, tend toclose said angle, such closure being prevented by abutment means,whereby the door sections are held in a position of equilibrium.

SUMMARY OF THE INVENTION In accordance with the invention the objectiveis achieved by providing a foldable door having an upper and lower doorsection. The lower door section is hingedly connected to the upper doorsection about a horizontal- 1y disposed axis and guide track means aredisposed along the edges of the door for guiding the lower door section.Pivotable means are disposed near the top edge of the upper doorsection. Biasing means mounted on one of the door sections and engagingthe other door section by movable connection means, the movableconnection means exerting on the other door section a leveragecompensating for the change in tension which occurs in the biasing meansas the angle between the door sections varies during opening and closingof same.

A preferred construction of folding door according to the invention(particularly suitable for application to the back of a delivery van),is hereinafter described by way of example with reference to theaccompanying drawings, wherein:

FIGURE 1 is a side sectional elevation showing the folding door whenfully open,

FIGURE 2 is a similar view of the door in its closed position, and

FIGURE 3 is an elevation corresponding to FIGURE 2, with the doorclosed, as seen from inside a van body.

Referring to the drawings, the door opening to be covered by the door isdefined at the top by the head rail 1, and at each side by posts 2, asis customary. In the case of a van body, as shown, the rail 1 may adjointhe roof 3.

The door comprises two sections 4, 5 hinged together by hinges 6 so asto be foldable about a horizontal axis. The upper door section 4 issuspended from hinge pins 7 mounted on the side of the head rail 1remote from that on which the door opens. The leaves 8 of the hinges towhich the door section 4 is secured are extended to form substantiallyU-shaped arms as viewed in FIGURES 1 and 2, said arms passing throughthe door opening. Thus, when the door is in the open position as shownin FIG- URE 1, the upper portion of the door section 4 is raised LbOVCthe door opening, while when the door is closed ts shown in FIGURE 2,the hinges are not visible from the )ther side of the door, i.e. theoutside. The shape of the 1inges and the position of the hinge pins 7 inrelation to ;he head rail are such that when in its fully open position;he hinge arms 8 rest against the lower side of the head rail. At thebottom of the lower door section is mounted, it each side, a roller 9which engages an upright guide track 10 secured to the post 2. Therollers 9 are preferably adjustable vertically in relation to theirposition as seen in FIGURE 3.

It will be evident that with this construction, when the door is fullyclosed, the door sections 4 and 5 will lie in the same plane, as shownin FIGURE 2. In order to open the door, the hinge 6 connecting the twosections is moved outwards, in the direction of the arrow A in FIGURE 2.A handle 20 may be provided on the outside of the door section 5 toenable it to be moved upwards, while, if desired, a second handle 21 maybe mounted near the hinge 6 to enable the latter to be pulled outwards.The lower edge of the door section 5 is constructed to move verticallyby the engagement of the rollers 9 with the tracks 10, while the hinges8 move the upper door section 4 into a raised position, as shown inFIGURE 1, until ultimately the lower door section may be substantiallyhorizontal in position immediately below the head rail 1. Full use maythus be made of the door opening.

According to the present invention, the weight of the door sections issubstantially counter-balanced during the pivotal movement thereof, andthis is achieved by spring means tending to close the hinge 6. This maybe eifected in several ways, but the construction shown in the drawingsis particularly simple and effective. Coil springs 12 are mounted in amedial position on the door section 4, as shown more clearly in FIGURE3. The springs are mounted on a rod or tube carried by angle members 13and their tension can be adjusted in known manner. At one end thesprings are extended and telescopically secured in an adjustable mannerto arms 14, the free ends of which extend across the axis of the hinges6 and carry rollers 15 which engage in a guideway 16 secured to the doorsection 5. The angle members 13 carrying the springs 12 are alsoadvantageously adjustable on the door section 5.

The springs 12 are suitably tensioned so that a leverage is appliedtending to close the hinges 6. This has the effect of tending to movethe door sections from the position shown in FIGURE 2 to the positionshown in FIGURE 1, in which the door section 5 can be raised no farther,the rail 1 acting as an abutment limiting the upward movement of saiddoor sections. It will be evident from a consideration of FIGURES 1 and2, that when the parts are in the position shown in FIGURE 2, althoughthe springs are fully tensioned, the leverage exerted on the doorsection 5 tending to turn it about the hinges 6 is relatively small. Bysuitable adjustment of the angle members 13 in a vertical directioncombined with adjustment of the telescopic arms 14 the most advantageouspoint along track 16 for applying the spring pressure may be selected.If, to open the door, the handle 21 is pulled in the direction of arrowA, the component of the weight of the door section 5 (as well as that ofthe door section 4) resisting the pull upon the handle is relativelysmall, so that the doors move easily during this initial movement aided,of course, by the action of the springs 12. As the movement proceedsfurther, however, the leverage exerted upon the door section 5 by thesprings 12 increases as the rollers 15 move along the guideway 16, thecomponent of the weight of the door sections resisting such movement asthe doors swing into their fully raised position, may be entirelycounterbalanced in spite of the fact that the springs partially unwindduring this movement. In order Words, the change in the position of thepoint of application of the force exerted by the spring arms 14 on thedoor section 5 compensates for the partial unwinding of ing to fold thelower door section towards the upper door section may therefore increaseas the sections close together, in which case the door will remain in araised position until the handle 20 is pulled downwards.

It, is however, not necessary to rely upon the efiect of the springs 12to retain the door sections in the position in which the lower doorsection is fully raised. By suitable choice of the dimensions andarrangement of the hinges 6, the position of the tracks 10 in relationthereto, and the relative measurements of the door section, the resultmay be achieved that when the lower door section 5 is horizontal theweight of the door sections 4 and 5 acting downwards will cause areaction between the rollers 9 and the tracks 10 in a directionperpendicular to said tracks and passing near to the axis of the hinge6. When this reaction intersects the hinge axis, the parts will be inunstable equilibrium, whereas if the line of action of said reactionpasses above said hinge axis the two door sections will tend to closetogether by reason of their own weight. Such closure will be prevented,however, if further upward movement of the rollers 9 in the tracks 10 isblocked. Therefore, in the preferred construction according to theinvention the head rail 1 affords an abutment preventing further upwardmovement of the adjacent portion of the lower door section just when theposition of unstable equilibrium above mentioned is passed upon theraising of the lower door section. In this position said door sectionwill be approximately horizontal as shown in FIGURE 1, while the anglebetween the two door sections is preferably between 10 and 15.

It will thus be apparent that the door sections will tend to remain inthe fully raised position by reason of their .own weight andirrespective of the action of the springs 12, and this condition is notaffected even if the van or the like on which the door is mounted standson a gradient. The effect produced is to offer a definite resistance tothe initial downward movement of the door sections when the handle 20 ispulled to lower the door, until the point of equilibrium is passed,beyond which the weight of the door sections acting downwards isresisted only by the tension of the springs 12.

Thus, by the construction according to the invention the doors may beraised or lowered by the application of a very small force to the handle20 or 21 in the desired direction of movement. The doors are firmly heldwhen raised, as described, in the preceding paragraph, while latchmeans, not shown, may be provided if desired to secure the doors intheir fully closed positions. Other refinements may be added if desired,for example, a small drainage channel 17 (FIGURES 1 and 2) may beprovided in association with the hinges 8 to catch and conduct laterallyany moisture entering between the top of the door section 4 and the toprail 1 when the door is raised, together with a deflector 18 mounted onthe top rail. Alternatively, a flexible cover may be Provided to coverthe space between said rail and the adjacent edge of the door section.The door sections may also be sealed along their side edges when closedso as to prevent the ingress of dust and moisture, and the sections maybe made of any desired thickness to afford thermal insulation.

The invention is applicable not only to the rear doors of vans, butwherever doors of the kind referred to may be required, for example, asdoors for garages, containers, as window shutters and so forth, toenable substantially the full door opening to be unobstructed when thedoor is opened.

What is claimed is:

1. A foldable door comprising an upper door section, a lower doorsection hingedly connected to said upper door section about ahorizontally disposed axis and guide track means disposed along theedges of said door for guiding said lower door section, pivotal meansnear the top edge of said upper door section, and biasing means thespring as the door is raised. The turning moment tendmounted on one ofsaid door sections and engaging said other door section by movableconnection means, said movable connection means exerting on said otherdoor section a leverage compensating for the change in tension whichoccurs in said biasing means as the angle between said door sectionsvaries during opening and closing movement of said door sections.

2. The foldable door according to claim 1, wherein said movableconnection means is slidable relative to said lower door section tocounter-balance a proportion of the weight of said door sections and tocompensate for the change in tension which occurs as the angle betweensaid door sections varies.

3. The foldable door according to claim 2, wherein said biasing means isa spring.

4. A foldable door comprising an upper section, a lower section hingablyconnected to said upper section and guide track means disposed along theside edges of said door for guiding said lower section, pivotable meansnear the top edge of said upper section, spring means secured to one ofsaid door sections in a medial position and adapted to exert a leverageupon the other door section whereby said sections tend to foldback-to-back toward each other about said hinge, the point ofapplication of the spring force tending to fold said door sectionstoward each other being a function of the angle between said doorsection and movable to compensate for the change in spring tension whichoccurs as the angle between said door sections varies, and said springexerting a turning movement upon the other door section by means of alever arm, the free end of which has a movable connection with saidother door section.

5. The foldable door according to claim 4, wherein said movableconnection of said lever arm is provided by a guideway on one of saiddoor sections in which is engaged a roller carried upon the free end ofsaid lever arm, the other end of which is connected to the springmounted on said other door section.

6. The foldable door according to claim 4, wherein said lever arm is atelescopic member.

7. The foldable door according to claim 4, wherein the position of theanchorage of said spring to one of the door sections is adjustable.

8. A foldable door according to claim 5, wherein said doors are hingedand arranged such that when said lower door section is in its fully openposition said upper door section lies at an angle thereto, and saidlower door section is in a position relative to said guide tracks thatforces which act on said lower door section, due to its respectiveweight and the reaction of said guide tracks, tend to close said angle,and abutment means preventing such closure and maintaining said doorsections in equilibrium.

9. The foldable door according to claim 8, wherein said abutment meansis adapted to stop the further upward movement of the lower door sectionimmediately after said lower door section passes the position in whichit extends perpendicularly from said guide tracks when being moved intoa fully open position.

10. The foldable door according to claim 1, wherein said pivotable meanscomprises hinges mounted adjacent to a horizontal rail defining the topof the door opening, the axis of said hinges being on the opposite sideof said rail to that on which the door is adapted to open, and saidhinges being shaped so that the upper portion of said upper door sectionis raised above said opening when said foldable door is fully open.

11. The foldable door according to claim 9, wherein said horizontal railof the door opening provides the abutment means for said lower doorsection limiting the opening movement of same when said lower doorsection is in a substantially horizontal position.

12. The foldable door according to claim 10, wherein said lower doorsection is in a position of maximum opening when said upper door sectionis disposed at an acute angle thereto of between about 10 and 15.

13. The foldable door according to claim 10, wherein said door openingis part of a truck van body.

References Cited UNITED STATES PATENTS 784,896 3/ 1905 Schommer -207 X1,529,973 5/1927 Rush et a1 160-207 1,716,394 6/1929 Trammell 160-1912,274,216 2/1942 Sanders 160-207 X 2,362,789 11/1944 Workman 160-1902,592,027 4/1952 Hagerup 160-191 2,722,273 11/1955 Taylor 160-1913,085,622 4/1963 Burgin 160-207 X DENNIS L. TAYLOR, Primary Examiner US.Cl. X.-R. 160-192

